

Book II. ROADS OF VARIOUS ENGINEERS. .579 



Subsect. 3. Road-making, as treated of and practised by various eminent Engineers and 



Surveyors. 



3594. The subject of forming a road may be considered as to breadth, drainage, fences, 

 base of the hard materials or artificial stratum, upper line of the stratum, composition of 

 the stratum, size of the materials, laying, ami compressing. 



3595. With respect to breadth, the site of every public road, according to Marshal, 

 ought to be sufficiently ample to admit of its division into three travelable lines : namely, 



1. A middle road of hard materials, for carriages and horses in winter and wet seasons ; 



2. A soft road, formed with the natural materials of the site, to be used in dry weather, 

 to save the unnecessary wear of the hard road, and to favour the feet of travelling animals, 

 as well as for the safety, ease, and pleasantness of travelling in the summer season ; and 



3. A commodious path, for the use of foot passengers, at all seasons. There are few 

 roads, even in the environs of populous towns, so public as to require a hard road of 

 more than two statute poles (thirty-three feet) in breadth ; and every public road ought, 

 under ordinary circumstances, to have a line which is travelable at any season, and of 

 ample width to permit two carriages to pass each other with freedom and safety. This 

 ample width let us set down at one statute pole. In deep clayey districts, where hard 

 materials are difficult to be procured, a single road, of half a pole in breadth, with dila- 

 tions at proper distances, to let carnages pass each other, may, in many recluse situations, 

 be advisable. 



3596. Seventy feet in width seems to be considered by Farey, Walker, Telford, and 

 most engineers, as sufficient near the largest towns ; and in the case of the metropolis and 

 some others, they consider that ten or twenty feet in width may be paved. The London 

 Commercial road, executed under the direction of Walker, is seventy feet wide ; ten 

 feet on each side are occupied as footpaths, twenty feet in the centre are paved for heavy 

 carriages, and there are fifteen feet of gravel road at each side for light carriages and 

 saddle horses. This road has been executed for sixteen years, and has given the greatest 

 satisfaction ; but Walker thinks that considerable improvement would be found from 

 paving the sides of a road, upon which the heavy traffic is great in both directions, and 

 leaving the middle for light carriages. The carmen or drivers, walking upon the foot- 

 paths or sides of the road, would then be close to their horses, without interrupting or 

 being in danger of accidents from light carriages, which is the case when they are driving 

 upon the middle of the road ; and the unpaved part being in the middle or highest part 

 of the road, would be more easily kept in good repair. But unless the heavy traffic in 

 both directions is great, one width, say ten or twelve feet, if very well paved, will be 

 found sufficient ; and in this case, the paving ought to be in the middle of the road. 

 The width of many of the present roads is, besides, such, that ten or twelve feet can be 

 spared for paving, while twice that width would leave too little for the gravelled part. 

 Although the first cost of paving is so great, he does not think that any other plan can 

 be adopted so good and so cheap in those places where the materials got in the neigh- 

 bourhood are not sufficient for supporting the roads. A coating of whinstone is, for 

 instance, more durable than the gravel with which the roads round London are made 

 and repaired, but much less so than paving ; although the freight and carriage of the 

 whinstone, and of the paving stones, which form the principal items of the expense, 

 are nearly the same. 



3597. Roads ought to be wide and strong, Edgeworth observes, in proportion to their 

 vicinity to great towns, mines, or manufactories. As they approach the capital, they 

 should be wider and stronger than elsewhere. When a number of roads leading to a 

 great city combine and fall into one, the road from that junction should be proportion- 

 ably solid and capacious. Near the capital, the width of roads is however often restricted 

 by buildings, that cannot with propriety be suddenly removed ; but every opportunity for 

 removing these buildings, and for widening the road, should be attended to, and no 

 future buildings or encroachments should be allowed. And, though in some cases it 

 appears reasonable to permit the erection of new buildings, and the making new plant- 

 ations, nearer than thirty feet from the centre of a road, upon condition that security 

 should be given to the public for the constant preservation of the road that is thus 

 injured ; it is, however, far safer to prohibit what is injurious to public convenience, than 

 to compromise with individuals : cases of private hardship may and must occur, but it is 

 part of the true glory of Britain that there exists no exemption in our laws in favour of 

 the rich. 



3598. Proportioning the breadth of roads to the traffic for which they may be employed 

 is not sufficiently attended to. In remote places, where there is but little traffic, the 

 waste of ground, occasioned by superfluous width of roads, is an error of considerable 

 magnitude. There are many places where roads of twenty feet in breadth would suit 

 the public convenience, as well as if they were twice as broad. Now it is clear, that if a 

 road is one pole or perch wider than is necessary, there is a waste of 320 perches in a 



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